Not tov start another debate about the color of something online, but that looks very much like an inventory sticker. The blue ones are much lighter blue than that. That is a black sticker, and the glare bouncing off of it makes it look lighter
Guys, this happens from time to time and there's nothing you can do about it. Sometimes, life changing events can happen in a flicker of an eye, and it might make you feel powerless, but choose instead to be humbled by it. We are not gods.
Edit: I did not read OP's post text. I thought this was about computer stickers... sorry, everyone.
I could see it as being a part of some internal identification system they use. To keep track of pets, urns, or what is being worked on a particular day. Maybe which urns have been reserved and which are free to use.
What I think may have happened
Someone cut the stickers and left it on top of whatever they were supposed to identify, for someone else to use later
It was never used or needed, and fell in with the stuff that was sent to you
Best way to confirm would be to ask, I'm sure they wouldn't mind confirming!
If you stick it to something and then peel it off, does it leave a symbol? They have tamper detection stickers that leave a design when peeled off but they may not have used it on yours as it appears to be a fabric.
Is there a way I can tell? I’m pretty techy, but not familiar with that technology. It looks like a regular black sticker to me, and feels like it has a smooth finish. I tried looking that up and get nothing but sites trying to sell me nfc stickers.
I think you put it on the bottom of the urn and write your pet's name on it. I have four tiny urns on my bookcase now and labeling them has proved important.
What size is the sticker? All I can think is it would be used as a way to help seal the urn/container? If you got the urn from a veterinarian you could reach out to them and ask, maybe it was included accidentally?
The Black Spot is a literary device invented by Robert Louis Stevenson for his novel Treasure Island (serialized 1881–82, published as a book in 1883).
My guess is it is an anti-tamper sticker. Once applied to a surface, removing it leaves behind a decal so that it would be obvious should the sticker be reapplied.
Best guess is that it is supposed to have been used to make sure remains are not mixed up. Black sticker with the paperwork and black sticker with the remains with black sticker with the urn sort of thing.
Best answer would come from the burners, call them and find out.